This document relates to wireless communications in wireless communication systems.
Wireless communication systems can include a network of one or more base stations to communicate with one or more wireless devices such as a mobile device, cell phone, wireless air card, mobile station (MS), user equipment (UE), access terminal (AT), or subscriber station (SS). Each base station emits radio signal that carry data such as voice data and other data content to wireless devices. A base station can be referred to as an access point (AP) or access network (AN) or can be included as part of an access network or a base station subsystem (BSS). Further, a wireless communication system can include a core network that is in communication with one or more base stations. A base station can transmit a radio signal on a forward link (FL), also called a downlink (DL), to one or more wireless devices. A wireless device can transmit a radio signal on a reverse link (RL), also called an uplink (UL), to one or more base stations.
Wireless technologies such as ones based on High Rate Packet Data (HRPD) uses reverse link signaling to provide feedback information of a forward link condition to a base station. Based on the feedback information, the base station can select a modulation scheme and coding rate for the receiving radio environment at the wireless device. To assist a base station to demodulate and decode reverse link data, a wireless device can transmit a data rate indication associated with data transmitted over the reverse link traffic channel. A wireless device can transmit feedback information such as Data Rate Control (DRC) information and Data Source Control (DSC).
A physical (PHY) layer in a wireless technologies can include a single carrier multi-link feature. For example, a wireless communication system can transmit data over two or more forward links. Supporting single carrier multi-link can include providing two or more reverse link connections such as separate reverse link long codes mask to transmit two or more sets of DRC and DSC information for control of first and second forward links respectively. In some wireless communication systems, a PHY layer includes forward link multiple-in-multiple-out (MIMO) communications. Feedback for MIMO communications can include using two or more reverse link overhead channels for the feedback of forward link condition. Various examples of MIMO based overhead channels include a Spatial Signature Indication (SSI) used to indicates pre-coding matrix Index and a Spatial Rank Indication (SRI) used to indicate channel dimensionality.